AQA A LEVEL BIOLOGY PAPER 3
JUNE 18 2025 MERGED QUESTION
PAPER AND MARK SCHEME 2026
COMPLETE QUESTIONS AND
VERIFIED ANSWERS GRADED A+
◉ What is the primary structure of a protein? Answer: The sequence of
amino acids
◉ What are the steps in binary fission? Answer: 1. Replicate circular
DNA 2. Replicate plasmids 3. Cytoplasm divides into two genetically
identical daughter cells
◉ What is the effect of Bedaquiline? Answer: Inhibition of ATP
synthase
◉ Where are ADH receptors present? Answer: In the distal convoluted
tubule (DCT) and collecting duct
◉ Where is water absorbed in the nephron? Answer: From filtrate in the
proximal convoluted tubule (PCT), distal convoluted tubule (DCT), and
collecting duct
◉ Why can't plasma proteins pass through the basement membrane?
Answer: They are too large
JUNE 18 2025 MERGED QUESTION
PAPER AND MARK SCHEME 2026
COMPLETE QUESTIONS AND
VERIFIED ANSWERS GRADED A+
◉ What is the primary structure of a protein? Answer: The sequence of
amino acids
◉ What are the steps in binary fission? Answer: 1. Replicate circular
DNA 2. Replicate plasmids 3. Cytoplasm divides into two genetically
identical daughter cells
◉ What is the effect of Bedaquiline? Answer: Inhibition of ATP
synthase
◉ Where are ADH receptors present? Answer: In the distal convoluted
tubule (DCT) and collecting duct
◉ Where is water absorbed in the nephron? Answer: From filtrate in the
proximal convoluted tubule (PCT), distal convoluted tubule (DCT), and
collecting duct
◉ Why can't plasma proteins pass through the basement membrane?
Answer: They are too large
